Professional
Issues
Water Fluoridation in Canada: Past and Present
Contact Author
Danielle Rabb-Waytowich, MLIS
Ms. Rabb-Waytowich
Email:
library@cda-adc.ca
ABSTRACT
Water fluoridation remains a contentious issue in Canada and many communities choose
not to fluoridate their water supply. As of 2007, 45.1% of the Canadian population had
access to fluoridated water supplies. The main arguments for and against fluoridation
have changed very little over the years, with supporters (including the World Health
Organization and Health Canada) citing evidence that shows fluoridation as a safe and
effective method of caries prevention, while detractors cite high costs and potential
health risks. This article provides an historical overview and a current snapshot of water
fluoridation in Canada. It concludes that the ultimate advantage of fluoridation is that it
helps everyone in a community, regardless of socioeconomic status.
For citation purposes, the electronic version is the definitive version of this article: www.cda-adc.ca/jcda/vol-75/issue-6/451.html
T
he Centers for Disease Control and
Prevention (CDC) calls it “one of the 10
great public health achievements of the
20th century.”1 The World Health Organization
(WHO) considers access to this substance to
be a part of the basic human right to life.
Countless researchers, professional associations and organizations support having it in
our water supply. So why then is water fluoridation still so controversial?
The link between fluoride and its benefits in the reduction of caries was discovered
in the early 1930s by Dr. H. Trendley Dean
of the U.S. National Institutes of Health. Dr.
Dean is credited with making the formal link
between fluoride and the reduction of caries.
His research originally focused on the consequences of too much fluoride in drinking
water (namely mottled enamel), but his work
pointed to the benefits of what a little fluoride
could do. 2 After years of research, Grand
Rapids, Michigan, became the first city in the
world to intentionally add fluoride to its water
as part of a case study in 1945. The nearby
city of Muskegon, Michigan, acted as the nonfluoridated control group for the study. 3
Around the same time, the cause was taken
up in Canada by Dr. W.L. Hutton, medical officer of health for the Brant County Health
Unit. In 1945, Brantford, Ontario, became the
first Canadian city to add fluoride to its water.
Brantford was paired with neighbouring
Sarnia in an 11-year case study of the effects of
water fluoridation. Over this period, Brantford
children had a 63% reduction in the severity of
caries and a 35% reduction in the prevalence
of caries.4 Since the time of these early case
studies, the rate of community water fluoridation in Canada has grown, with 45.1% of the
total population now having access to fluoridated water (Table 1, Box 1).5
Water Fluoridation in Canadian
Municipalities
The decision to fluoridate water supplies is
made by local governments, with the federal,
provincial and territorial governments setting
the guidelines. Even though the decision to
fluoridate water supplies falls upon the municipalities, there are significant trends among
the provinces regarding community water
JCDA • www.cda-adc.ca/jcda • July/August 2009, Vol. 75, No. 6 •
451
––– Rabb-Waytowich –––
Table 1 Provincial and territorial estimates for community water fluoridation coverage in 20075
Total
population
Population
with fluoridated
water
Population
without
fluoridated
water
Percentage
with
fluoridated
water
Percentage
without
fluoridated
water
British Columbia
4,113,000
152,241
3,960,759
3.7%
96.3%
Alberta
3,290,350
2,457,406
832,944
74.7%
25.3%
968,157
356,096
612,061
36.8%
63.2%
1,148,401
803,116
345,285
69.9%
30.1%
Ontario
12,160,282
9,229,015
2,931,267
75.9%
24.1%
Quebec
Province
Saskatchewan
Manitoba
7,546,131
489,420
7,067,711
6.4%
93.7%
New Brunswick
729,498
188,607
540,891
25.9%
74.2%
Nova Scotia
913,462
519,031
394,431
56.8%
43.2%
Prince Edward Island
135,851
32,174
103,677
23.7%
76.3%
Newfoundland/Labrador
505,469
7,572
497,897
1.5%
98.5%
Nunavut
29,474
0
29,474
0.0%
100.0%
Northwest Territories
41,464
23,400
18,034
56.4%
43.6%
Yukon
30,372
0
30,372
0.0%
100.0%
31,611,911
14,258,078
17,364,803
45.1%
54.9%
Canada
Table reproduced with permission.
fluoridation. Ontario, Alberta and Manitoba have the
highest percentage of community water fluoridation with
rates of 75.9%, 74.7% and 69.9% respectively. At the other
end of the scale, the lowest rates of water fluoridation can
be found in British Columbia (3.7%), Newfoundland and
Labrador (1.5%) and Nunavut and the Yukon (0%). The
latter 2 regions do not fluoridate their water at all.
The Debate Over Water Fluoridation
Despite fluoride being introduced into Canadian
communities over 60 years ago, the national average still
currently sits at less than 50%. Clearly water fluoridation
is not without its detractors, and over the years, the principal arguments for and against water fluoridation have
changed very little. Those in favour of water fluoridation
have supporters such as the WHO, the CDC, Health
Canada, the Public Health Agency of Canada along with
American and Canadian dental and allied health associations, such as CDA, the Canadian Association of
Public Health Dentistry, the Canadian Dental Hygienists
Association, the Royal College of Dental Surgeons of
Ontario, the Canadian Pediatric Society and the Canadian
Medical Association.
These groups point to the proven benefits of water
fluoridation in Canada. “Canada has one of the best systems in the world to ensure water quality. Health Canada
supports water fluoridation as a public health measure
to prevent dental decay. Dental disease is the number
452
one chronic disease among children and adolescents in
North America; fluoridation can therefore be an important public health measure,” says Dr. Peter Cooney,
Health Canada’s Chief Dental Officer. “The big advantage
of water fluoridation is that it benefits all residents in a
community, regardless of age, socioeconomic status, education or employment.”
Research continues to show that water fluoridation is
effective in reducing tooth decay by 20% to 40%.6 In 2009,
analyzing data on a city-by-city basis is more challenging
as populations are exposed to fluoride through a variety
of sources such as toothpastes, fluoride treatments at the
dental clinic, natural low-level fluoride in water and food
manufactured in fluoridated regions being shipped to
non-fluoridated communities. These factors can sometimes mask the true effects of water fluoridation.
Certain cities in close proximity have been able to
isolate rates of caries in their jurisdictions. For example,
in the tricity area of Kitchener-Waterloo-Cambridge in
Ontario, the rate of caries in children is 44% in Kitchener
(0.1 parts per million [ppm] naturally occurring fluoride),
33% in Cambridge (0.3 ppm naturally occurring fluoride)
and 32% in Waterloo (where water has been fluoridated
since 1967).7 Even though Kitchener and Cambridge have
naturally occurring fluoride in their water, these levels
are well below the minimum rate of effectiveness of fluoridated water, which is considered to be 0.5 ppm.7
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Box 1 Snapshot of water fluoridation in Canada (percentage of population with fluoridated water)
Ontario (75.9%)
Since 2008, the fluoridation debate in Ontario has been very active. At least 8 communities were challenged to discontinue community water fluoridation. Municipal councils voted to continue fluoridation in Hamilton, Tottenham and Atikokan.
Dryden (by referendum) and Niagara (by regional council) voted not to restart its water fluoridation program. Halton and
Norfolk councils voted to continue fluoridation while awaiting the final report of the Federal-Provincial-Territorial Committee
on Drinking Water. Thunder Bay, which is not fluoridated, has implemented a public education program on community water
fluoridation. Waterloo’s water supply is currently fluoridated, with a future plebiscite scheduled for the 2010 municipal elections. Other Ontario cities have decided to adjust their fluoride levels, with Toronto and Hamilton lowering their levels to
0.6 parts per million.
Quebec (6.4%)
In 2008, Quebec City voted to discontinue water fluoridation, while Dorval resumed fluoridation after a 5-year hiatus.
Montreal’s water supply remains non-fluoridated.
Nova Scotia (56.8%)
Fluoridation in Nova Scotia began in the 1970s. Currently, 57% of the population has access to fluoridated water. The province has a fluoride mouthrinse program offered in select schools for children 4–12 years of age. The Nova Scotia Department
of Health Promotion and Protection supports the fluoridation of drinking water to help prevent caries (see the department’s
position statement at: www.gov.ns.ca/hpp/publications/position_statement-fluoridation.pdf).
Alberta (74.7%)
Calgary went through 5 plebiscites on fluoride up to 1998. A vote in 1989 received a majority, and water fluoridation
started in 1991. A plebiscite held in 1998 resulted in a narrow victory for water fluoridation (55% voted yes). Edmonton has
fluoridated its water since 1967.
British Columbia (3.7%)
Despite the British Columbia Ministry of Health Services supporting water fluoridation in the prevention of caries, less than
4% of B.C. community water is fluoridated.
Newfoundland/Labrador (1.5%)
Only 1.5% of the province’s community water is fluoridated, down from 3.5% in 2005. Most private and community water
sources in the province come from wells which may have natural sources of fluoride (see the map “Areas of potential fluoride
concentration in well water” at: www.env.gov.nl.ca/Env/env/waterres/Groundwater/Fluoride/GW&Fluoride.asp).
Prince Edward Island (23.7%)
A plebiscite on fluoridation was held in Charlottetown in 1967. Fluoridation began in 1968 in this city as well as the
Canadian Forces Base in Summerside. Currently, P.E.I. is focusing on preventive dental programs for children and adolescents
through schools, which include topical fluoride application for the partial prevention of tooth decay.
In another study, the Simcoe Muskoka District Health
Unit (which has largely non-fluoridated communities)
compared its rate of decay in children 5 to 13 years of
age against the rates of decay in 36 health units across
Ontario.8 The study’s results showed that the children
of Simcoe Muskoka had consistently higher rates of
decay.
Advocates against water fluoridation cite arguments
relating to the cost of water fluoridation (estimated at
$0.60 to $1.00 per person, per year), environmental
pollution and alleged health risks such as dental and
skeletal fluorosis, cancer, low IQ levels, bone fractures,
immuno-toxicity, reproductive/developmental toxicity,
genotoxicity and neurotoxicity. Others believe fluoridation is an infringement on human rights. The bottled
water industry has even launched advertising campaigns
picking up on this negative sentiment, offering its products as a fluoride-free alternative.
Research supporting both sides of the fluoride debate
exists, yet both camps accuse the other of “cherry picking”
research to boost its argument. The reality, however, is
that credible scientific research continues to support the
conclusion that water fluoridation is safe at optimal levels
and is an effective means of caries prevention.4,6
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453
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In Support of Water Fluoridation
In April 2008, Health Canada released its findings and
recommendations from a Fluoride Expert Panel.9 This
panel was brought together in January 2007 to provide
expert advice and recommendations to Health Canada
and the Federal-Provincial-Territorial Committee on
Drinking Water regarding the optimal levels of fluoride
in drinking water. Health Canada commissioned the
panel to ensure exposure to fluoride remains below levels
that could cause adverse effects (i.e., moderate and severe
dental fluorosis), while achieving the public health benefit
of preventing dental caries. The areas of study focused
on total daily intake of fluoride, dental fluorosis, other
health effects, risk assessment and the risks and benefits
of drinking fluoridated water.
The panel concluded that 0.7 mg/L ppm of fluoride
in drinking water suitably protects against dental caries
while minimizing the risk of dental fluorosis. This
figure was reduced from the previous range of 0.8 to
1.0 mg/L ppm, to help prevent excessive intake of fluoride
through multiple sources of exposure. The panel also
concluded that the maximum allowable concentration
should remain at 1.5 mg/L ppm. The panel found no
health concerns with the prevalence of very mild and
mild dental fluorosis. It considered moderate dental
fluorosis to be the cosmetic end-point (as opposed to
a toxicological end-point), and noted that the prevalence of moderate dental fluorosis is low in Canada and
decreasing.
The panel supports community drinking water fluoridation as an effective public health measure in reducing
the prevalence of dental caries in Canada. It also recommended that the infant formula industry lower and
standardize the fluoride concentration in formula as it
was found to have the greatest variability. They found no
evidence to link fluoride with an increased risk of cancer,
bone fracture, immunotoxicity, reproductive/developmental toxicity, genotoxicity or neurotoxicity. Skeletal
fluorosis is an adverse effect associated with excessive
fluoride exposure, which is likely to occur if an individual
ingests 10 mg of fluoride per day for 10 years or more.
Currently, oral health data is being collected through
the Canadian Health Measures Survey (CHMS). The
CHMS is measuring key health information about
Canadians through a household questionnaire followed
by direct clinical measurements. These clinical measurements include a clinical oral examination phase, which
will establish a national baseline level of the decayed,
missing and filled teeth (DMFTs) for Canadians and a
national level of fluorosis for children 6–11 years of age.
However, the survey will not provide accurate comparisons on the effects of fluoride in different communities
due to study design limitations.
454
Public health units and dental practitioners across the
country have made great strides in educating the public
on the benefits of fluoridated water. The main advantage
of water fluoridation is that it helps everyone in a community, especially those of lower socioeconomic status.
Not everyone has the means or opportunity to go to the
dentist on a regular basis or practise good oral health
habits.
Dentists are often on the front lines of the water
fluoridation debate, answering tough questions from patients. CDA is working with Health Canada to compile
a comprehensive list of resources, along with Question
and Answer material for dentists, on water fluoridation. These online resources, which will be posted on the
CDA website, will help dentists as they continue to promote the benefits of water fluoridation and dispel the
myths of this scientifically proven, public health preventive measure. a
The Author
Ms. Rabb-Waytowich is acting information specialist at the
Canadian Dental Association.
Correspondence to: Ms. Danielle Rabb-Waytowich, Canadian Dental
Association, 1815 Alta Vista Dr., Ottawa, ON K1G 3Y6.
This article has been peer reviewed.
References
1. Centers for Disease Control and Prevention. Ten great public health
achievements – United States, 1900-1999. MMWR Weekly. 1999;48(12):241–
3. Available: www.cdc.gov/mmwr/preview/mmwrhtml/00056796.htm.
2. Centers for Disease Control and Prevention. H. Trendley Dean, D.D.S.
MMWR Weekly. 1999;48(41):925. Available: www.cdc.gov/mmwr/preview/
mmwrhtml/mm4841bx.htm.
3. Crawford PR. Fifty years of fluoridation. J Can Dent Assoc. 1995;
61(7):585-8.
4. Ito D. Hot topic: Community water fluoridation in Ontario. Ontario Public
Health Association Monthly Ebulletin. March 2009. [cited 2009 Jun 1]
Available: www.opha.on.ca/media/ebulletins/Mar09/hottopic.shtml.
5. Community Dental Health Services Research Unit. Provincial and territorial
estimates for community water fluoridation coverage in 2007. Toronto:
Faculty of dentistry, University of Toronto; 2007.
6. Simcoe Muskoka District Health Unit. Municipal water fluoridation:
Position of the Simcoe Muskoka District Health Unit, April 2009. [cited
2009 June 1] Available: www.simcoehealth.org/Libraries/JFY_Health_Care_
Professionals/Position_Statement_fluoride.sflb.ashx.
7. Region of Waterloo Public Health. Water fluoridation. Physician’s Update.
February 2008. [cited 2009 Jun 1] Available: http://chd.region.waterloo.
on.ca /web/health.nsf/0/E7742A6975D6895E852570E50055EEFF/$file/
PHYSUP_FEB08.pdf?openelement.
8. Simcoe Muskoka District Health Unit. Snapshot of dental decay in children. Focus on HealthSTATS. January 2009. p. 4. [cited 2009 Jun 1] Available:
http://simcoemuskokahealthstats.org/ Img/Content / Focus%20Reports/
Oral%20Health%202009/oral%20health_FINAL.pdf.
9. Findings and recommendations of the Fluoride Expert Panel (January
2007). Health Canada. [cited 2009 June 1] Available www.hc-sc.gc.ca/
ewh-semt/pubs/water-eau/2008-fluoride-fluorure/index-eng.php.
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